0.15μm Y型栅高In沟道GaAs PHEMT低噪声器件设计

0.15μm Y-gate Low Noise GaAs PHEMT with High In-content Channel

设计了一种GaAs PHEMT低噪声器件。通过电子束直写手段实现了0.15μm Y型栅,对栅型优化以减小器件栅电阻和栅寄生电容。采用高In含量的沟道设计以改善沟道电子输运特性,采用InGaAs/GaAs复合帽层以改善欧姆接触特性,并通过低噪声工艺流程制作了4×50μm GaAs PHEMT器件。测试结果表明,器件fT达到80GHz,在10GHz处最小噪声系数小于0.4dB,相关增益大于10dB。对于0.15μm栅长GaAs PHEMT器件来说,这是很好的结果。

A GaAs PHEMT low noise device was designed and a 0.15 micron Y-shaped gate was achieved by electron beam lithography.The gate resistance and parasitic capacitance were both reduced by optimizing gate shape of the device.The channel electronic transport properties were improved by adopting high In content channel layer,and ohmic contact characteristics were improved by employing InGaAs/GaAs composite cap layer as well.Based on these,4×50μm GaAs PHEMT devices were obtained by a low noise fabrication process.Microwave measurements show that its fTis as high as 80 GHz,and noise measurement and analysis show that the device at 10 GHz demonstrates a NFminof less than 0.4dB,which is an excellent result for 0.15μm gate length GaAs PHEMT devices.